<template>
    <div class="component-upload-image">
        <el-upload 
            multiple 
            :action="uploadImgUrl" 
            list-type="picture-card" 
            :on-success="handleUploadSuccess"
            :before-upload="handleBeforeUpload" 
            :limit="limit" 
            :on-error="handleUploadError" 
            :on-exceed="handleExceed"
            ref="imageUpload" 
            :before-remove="handleDelete" 
            :show-file-list="true" 
            :headers="headers"
            :file-list="fileList" 
            :on-preview="handlePictureCardPreview" 
            :class="{ hide: fileList.length >= limit }">
            <el-icon class="avatar-uploader-icon">
                <plus />
            </el-icon>
        </el-upload>
        <!-- 上传提示 -->
        <div class="el-upload__tip" v-if="showTip">
            请上传
            <template v-if="fileSize">
                大小不超过 <b style="color: #f56c6c">{{ fileSize }}MB</b>
            </template>
            <template v-if="fileType">
                格式为 <b style="color: #f56c6c">{{ fileType.join("/") }}</b>
            </template>
            的文件
        </div>

        <el-dialog v-model="dialogVisible" title="预览" width="800px" append-to-body>
            <img :src="dialogImageUrl" style="display: block; max-width: 100%; margin: 0 auto" />
        </el-dialog>
    </div>
</template>

<script setup lang="ts">
import { getToken } from "@/utils/auth";
import { getCurrentInstance, ComponentInternalInstance, ref, Ref, watch, computed, ComputedRef } from 'vue';
import type { UploadProps, UploadFile, UploadUserFile } from 'element-plus';

// 定义 props 类型
interface Props {
    modelValue?: string | object | Array<string | object>;
    limit?: number;
    fileSize?: number;
    fileType?: string[];
    isShowTip?: boolean;
    uploadImgUrl?: string;
}

// 定义 emit 类型
interface Emits {
    (e: 'update:modelValue', value: string[] | UploadUserFile[]): void;
}

const props = withDefaults(defineProps<Props>(), {
    modelValue: undefined,
    limit: 5,
    fileSize: 10,
    fileType: () => ["png", "jpg", "jpeg"],
    isShowTip: true,
    uploadImgUrl: '/api/upload/uploadImg'
});

const { proxy } = getCurrentInstance() as ComponentInternalInstance;
const emit = defineEmits<Emits>();

// 定义响应式变量
const number: Ref<number> = ref(0);
const uploadList: Ref<UploadUserFile[]> = ref([]);
const dialogImageUrl: Ref<string> = ref("");
const dialogVisible: Ref<boolean> = ref(false);
const baseUrl: string = import.meta.env.VITE_APP_BASE_STATIC_API;
const uploadImgUrl: Ref<string> = ref(import.meta.env.VITE_APP_BASE_API + props.uploadImgUrl);
const headers: Ref<{ token: string }> = ref({ token: getToken() });
const fileList: Ref<UploadUserFile[]> = ref([]);
const showTip: ComputedRef<boolean> = computed(
    () => props.isShowTip && (props.fileType.length > 0 || props.fileSize > 0)
);

// 监听 modelValue 变化
watch(() => props.modelValue, val => {
    if (val) {
        // 首先将值转为数组
        const list = Array.isArray(val) ? val : (val as string).split(",");
        // 然后将数组转为对象数组
        fileList.value = list.map(item => {
            if (typeof item === "string") {
                if (item.indexOf(baseUrl) === -1) {
                    return { name: item, url: baseUrl + item };
                } else {
                    return { name: item, url: item };
                }
            }
            return item as UploadUserFile;
        });
    } else {
        fileList.value = [];
    }
}, { deep: true, immediate: true });

// 上传前loading加载
const handleBeforeUpload: UploadProps['beforeUpload'] = (file) => {
    let isImg = false;
    if (props.fileType.length) {
        let fileExtension = "";
        if (file.name.lastIndexOf(".") > -1) {
            fileExtension = file.name.slice(file.name.lastIndexOf(".") + 1);
        }
        isImg = props.fileType.some(type => {
            if (file.type.indexOf(type) > -1) return true;
            if (fileExtension && fileExtension.indexOf(type) > -1) return true;
            return false;
        });
    } else {
        isImg = file.type.indexOf("image") > -1;
    }
    if (!isImg) {
        proxy?.$modal.msgError(
            `文件格式不正确, 请上传${props.fileType.join("/")}图片格式文件!`
        );
        return false;
    }
    if (props.fileSize) {
        const isLt = file.size / 1024 / 1024 < props.fileSize;
        if (!isLt) {
            proxy?.$modal.msgError(`上传头像图片大小不能超过 ${props.fileSize} MB!`);
            return false;
        }
    }
    proxy?.$modal.loading("正在上传图片，请稍候...");
    number.value++;
    return true;
};

// 文件个数超出
const handleExceed: UploadProps['onExceed'] = () => {
    proxy?.$modal.msgError(`上传文件数量不能超过 ${props.limit} 个!`);
};

// 上传成功回调
const handleUploadSuccess: UploadProps['onSuccess'] = (res, file) => {
    if (res.code === 200) {
        uploadList.value.push({ name: res.data.fileName, url: res.data.fileUrl });
        uploadedSuccessfully();
        proxy?.$modal.msgSuccess("上传成功");
    } else {
        number.value--;
        proxy?.$modal.closeLoading();
        proxy?.$modal.msgError(res.msg);
        // @ts-ignore
        proxy?.$refs.imageUpload.handleRemove(file);
        uploadedSuccessfully();
    }
};

// 删除图片
const handleDelete: UploadProps['beforeRemove'] = (file) => {
    const findex = fileList.value.map(f => f.name).indexOf(file.name);
    if (findex > -1 && uploadList.value.length === number.value) {
        fileList.value.splice(findex, 1);
        emit("update:modelValue", listToString(fileList.value));
        return false;
    }
    return true;
};

// 上传结束处理
function uploadedSuccessfully() {
    if (number.value > 0 && uploadList.value.length === number.value) {
        fileList.value = fileList.value.filter(f => f.url !== undefined).concat(uploadList.value);
        uploadList.value = [];
        number.value = 0;
        emit("update:modelValue", listToString(fileList.value));
        proxy?.$modal.closeLoading();
    }
}

// 上传失败
const handleUploadError: UploadProps['onError'] = () => {
    proxy?.$modal.msgError("上传图片失败");
    proxy?.$modal.closeLoading();
};

// 预览
const handlePictureCardPreview: UploadProps['onPreview'] = (file) => {
    dialogImageUrl.value = file.url || '';
    dialogVisible.value = true;
};

// 对象转成指定字符串分隔
function listToString(list: UploadUserFile[]): string[] {
    return list.map(item => item.url?.replace(baseUrl, "") || "");
}
</script>

<style scoped lang="scss">
// .el-upload--picture-card 控制加号部分
:deep(.hide .el-upload--picture-card) {
    display: none;
}
</style>